Re: [patch] make electric-pair-mode smarter/more useful

[Dmitry Gutov]

On 14.12.2013 17:18, Stefan Monnier wrote:
> I'm not completely sure I understand our question w.r.t the code you
> quoted: the code you quoted adds the behavior globally, so it obviously
> wouldn't be set on a per-mode basis.

Yes, but if it's set via electric-layout-rules, to what value will this 
variable be set in e.g. js-mode?

If it'll include what's there currently, '((?\; . after) (?\{ . after) 
(?\} . before)), then to get the desired behavior I described previously 
(NOT to insert a newline after I just typed `{', or any other 
character), I'd have to modify it again in js-mode-hook.

IOW, turning on electric-layout-mode would turn on all 
electric-layout-related behaviors defined for a given major mode. Are we 
willing to remove electric newlines after `;', `{' and `}', by default, 
from any major mode where one of those might conceivably be followed by 
some character other than newline?

Speaking of cc-mode, I don't really program in C (though I'd like to 
continue learning it at some point), but if I did, I'm not sure I'd want 
the electric-layout-mode behavior there, but 
electric-pair-newline-between-pairs-rule would be useful.

> > For example, like described previously, if I want js-mode to only insert
> > electric newlines when I press return, will I have to modify
> > electric-layout-rules in js-mode-hook, and do so for any other mode I use
> > that sets this variable?
>
> I think setting it on a per-mode basis would be OK, but it wouldn't be
> set by the user but instead by the major mode, based on the usual coding
> style used for that mode.  E.g. we wouldn't set it in Lisp, but we'd set
> it in js-mode.

Yes. And similarly, if we have a separate minor mode, it will be 
disabled (maybe via some -inhibit variable) by some major modes.